# E-mail obfuscation role for Sphinx.

from docutils import nodes

# The obfuscation code was taken from
#
#   http://pypi.python.org/pypi/bud.nospam
#
# and was was released by Kevin Teague <kevin at bud ca> under
# a BSD license.

import re
import string

rot_13_trans = string.maketrans(
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
    'NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm'
)

def rot_13_encrypt(line):
    """Rotate 13 encryption.

    """
    line = line.translate(rot_13_trans)
    line = re.sub('(?=[\\"])', r'\\', line)
    line = re.sub('\n', r'\n', line)
    line = re.sub('@', r'\\100', line)
    line = re.sub('\.', r'\\056', line)
    line = re.sub('/', r'\\057', line)
    return line

def js_obfuscated_text(text):
    """ROT 13 encryption with embedded in Javascript code to decrypt
    in the browser.

    """
    return """<script type="text/javascript">document.write(
              "%s".replace(/[a-zA-Z]/g,
              function(c){
                return String.fromCharCode(
                (c<="Z"?90:122)>=(c=c.charCodeAt(0)+13)?c:c-26);}));
                </script>""" % rot_13_encrypt(text)

def js_obfuscated_mailto(email, displayname=None):
    """ROT 13 encryption within an Anchor tag w/ a mailto: attribute

    """
    if not displayname:
        displayname = email
    return js_obfuscated_text("""<a href="mailto:%s">%s</a>""" % (
        email, displayname
    ))

# -- end bud.nospam

def email_role(typ, rawtext, text, lineno, inliner, options={}, content=[]):
    """
    Role to obfuscate e-mail addresses.
    """
    text = text.decode('utf-8').encode('utf-8')
    # Handle addresses of the form "Name <name@domain.org>"
    if '<' in text and '>' in text:
        name, email = text.split('<')
        email = email.split('>')[0]
    else:
        name = text
        email = name

    obfuscated = js_obfuscated_mailto(email, displayname=name)
    node = nodes.raw('', obfuscated, format='html')
    return [node], []

def setup(app):
    app.add_role('email', email_role)